They browsed the cages and checked out nearly every dog available for adoption at the Toronto Humane Society, but after spending just minutes with Harley, a boxer-catahoula mix with big brown eyes and a tongue like a face-seeking missile, Ainsley Kendrick and Dian Miguel fell in love.

After the couple filled out the adoption paperwork, they expressed several concerns: the seven-month-old puppy couldn't seem to bear weight on her back left leg when she sat, and there was a pouch containing an empty pill container hanging from her cage.

Days after Ms. Kendrick, 28, and Ms. Miguel, 25, took Harley home, it became clear something was wrong.

What followed was a saga that culminated in the couple discovering they had brought home a seriously injured dog. Her leg was fractured and her kneecap severely displaced, a condition made worse by the Toronto Humane Society's inability to return their desperate requests for veterinary records. Left in the dark, Ms. Kendrick and Ms. Miguel had spent $526.21 in tests, X-rays and medication by the time their own vet confirmed that one of the country's largest animal shelters had given them a dog with a broken leg.

Ms. Kendrick said that when she did finally get through, the THS management said that they had made a mistake, that the dog shouldn't have been adopted, and that they would reimburse some of the costs.

"They're a shelter, they're supposed to be there for the protection of animals - and you just assume that it's a good place and you can trust them," Ms. Kendrick said. "It's really disappointing to find out that you can't."

Harley's attentive owners made her one of the society's luckier pets. An investigation by The Globe and Mail has found that the Toronto Humane Society is a shelter in crisis, a place where animals die suffering unnecessarily in their cages, according to veterinarians, significant amounts of money are spent on litigation, and the opinions of veterinary professionals are dismissed. According to insiders, its volunteer president, Tim Trow, has intimidated dozens of staff, volunteers and veterinarians into quitting out of protest. They vehemently disagree about the way he runs the shelter.

"It is heart-wrenching, I've watched critically ill animals suffer and die in my hands while I run around trying to get permission to euthanize," said Magdalena Smrdelj, a THS veterinarian.

Both know they're risking their positions by speaking to The Globe, as THS staff and volunteers are required to sign confidentially agreements. Both said that animal suffering inside the shelter was too great for them to remain silent.

Died Oct 19 3:15 am. Gasped and jerked and cried last breaths, because there was no one in shelter to euthanize or treat. This is not humane!
Written on the medical chart of a cat

Many of the people interviewed for the series signed confidentiality agreements effective for two years after leaving the shelter, and agreed to interviews despite the possibility that they could be sued for speaking out.

The Globe reviewed dozens of medical charts of animals left to die in their cages as a result of the shelter's much-too restrictive euthanasia policy, according to current and former staff and volunteers. The Globe also obtained pictures of cats and dogs living in their own excrement and interviewed more than 30 concerned current and former employees, volunteers, members and adoptive families - past and present - who have begged for help from the Ontario Society for the Prevention of Cruelty to Animals and the Canada Revenue Agency. They have also tried to enlist the College of Veterinarians of Ontario and Ontario's Ministry of the Attorney General, all to no avail.

They've discovered there is little anybody can do to rein in the THS, an independent organization virtually free from oversight, which is headquartered on River Street in Toronto's east end.

After disagreements over payment, the city ended its contract with the THS in 2001 and formed Toronto Animal Services. The last city councillor on the board left in 2006. The THS's relationship with the Ontario Society for the Prevention of Cruelty to Animals is strained and distant.